The report, released Monday by JupiterResearch, said online retail spending during November and December reached $22.1 billion, up 22 percent from the previous year.
The research firm attributed the increase to the surge in consumers who chose the 2004 holiday season to make their first online purchase.
"The holidays present a great opportunity for retailers to acquire new customers for the long term," Patti Freeman Evans, retail analyst at JupiterResearch, said in a statement. "Not only were millions of people shopping online for the first time, but three quarters of consumers bought from a site they had never purchased from before."
JupiterResearch's numbers fell near estimates released previously by other research firms. A similar study released last month from Goldman Sachs, Harris Interactive and Nielsen/NetRatings saidspent $23.2 billion, excluding travel.
JupiterResearch anticipates continued growth in 2005. The company predicted that online retail sales this year will reach $79 billion, about 20 percent more than the $66 billion spent in 2004.